Defending against wormhole attack in OLSR

OLSR (optimal link state routing) is one of the four basic routing protocols used in mobile ad hoc Networks by the MANET working group of IETF (Internet engineering task force). OLSR, a proactive routing protocol, is based on a multipoint relaying flooding technique to reduce the number of topology broadcast. OLSR uses periodic HELLO packets to neighbor detection. As introduced in Reference [1], the wormhole attack can form a serious threat in wireless Networks, especially against many ad hoc Network routing protocols and location-based wireless security systems. Here, a trust model to handle this attack in OLSR is provided and simulated in NS2.     

含裂隙碳酸盐岩酸化中超临界CO2对虫孔生长的影响初探

酸化是一种广泛应用于碳酸盐岩储层的增渗改造技术,其基本原理是将酸液注入储层裂隙,通过溶蚀反应使矿物溶解形成虫孔等通道,从而提高储层的渗透性和生产效率。以往的研究主要聚焦于优化注酸条件以提高成孔效率,忽略了碳酸盐岩酸化副产物CO2的影响。本研究针对三个含单裂隙的碳酸盐岩试样,开展不同浓度盐酸溶液的酸化实验,监测试样渗透率的变化;并在试验前后分别进行裂隙表面形貌激光扫描和内部空隙CT扫描,基于扫描结果对比分析了注酸条件对溶蚀效果的影响。研究结果表明：在流速、酸液浓度与种类等条件相同的条件下,CO2是否进入超临界态对虫孔形态有重要影响;超临界CO2可有效促进虫孔的生长,生成窄而长的虫孔,并显著提高溶蚀效果,试样的渗透率可提高3~9倍;而在CO2未进入超临界态的条件下,溶蚀形态接近面溶蚀或锥形虫孔,未贯通试样,试验前后渗透率没有显著变化,这是因为酸化反应产生的气态CO2会阻碍酸液的流动,从而降低酸化效果。本文结果揭示了在酸化中正面利用副产物CO2的可能性,有助于对现有酸化工程方案的优化和提升。     

Defending against wormhole attack in OLSR

IntroductionIn a multihop wireless ad hoc Network, mobilenodes cooperate to form a Network without u-sing any infrastructure such as access points orbase stations .Instead,the mobile nodes forwardpackets for each other ,allowing communicationamong nodes o…     

Quantum wormhole with conformal scalar field

In this paper I use the Hartle-Hawking method to discuss quantum wormhole with conformal scalar field. I derive the corresponding Wheeler-De Witt equation, calculate the wormhole wave function, which is found to be the product of two harmonic solutions. Analysis of the wave function reveals that the probability density of the wormhole appearing at a = 0 is zero, that the most probable radius of the wormhole base state is the Planck length and that the wormhole is mostly likely to be in a state of small Φ value.     

Thin-shell wormholes in non-linear f(R) gravity with variable scalar curvature

The present paper explores a thin-shell wormhole (TSW) developed by employing the cut and paste method to two copies of the black hole. It develops TSW in modified $f\left(R\right)$ theory of gravity with variable scalar curvature. The effects of the model parameters on the wormhole solutions are tested, the regions of linear stability are analyzed and stable wormhole solutions have been obtained.     

Møller energy momentum distribution for higher dimensional Morris Thorne wormhole

In this study, Møller energy momentum distribution is investigated for the higher dimensional Morris Thorne wormhole (MTW) in general relativity theory (GR) and results are given for the MTW in (4+1) and (5+1) dimensions. In addition, using the MTW, Møller energy and momentum distributions were investigated for 4-dimensional Morris Thorne wormhole, Hyperbolic Morris Thorne wormhole, Zero Tidal wormhole, Zero Density wormhole, Visser–Kar–Dadhich wormhole and (2+1) dimensional Morris Thorne wormhole. Except for the Zero Tidal wormhole model, we obtained the Møller energy distribution as well defined and non-zero in all other wormhole models. Besides, our results are in agreement with Aygün and Yılmaz and support Lesnner’s idea for Møller energy momentum definition.